PTPN11 and breast cancer: Src homology 2 domain containing protein tyrosine phosphatase-2 (SHP2) is a non-receptor protein tyrosine phosphatase that is ubiquitously expressed and plays a key role in many cellular pathways, regulating development, metabolism, and cell signaling across numerous species.1,2 The upregulation of SHP2 has been observed in various cancers (including leukemia, lung and breast cancers, and neuroblastomas) and other malignancies (such as Noonan syndrome and metachondromatosis),1,2 leading to interest in targeting SHP2 as a new anticancer drug target.